Carrie Underwood and Mike Fisher Celebrate Their Anniversary

"Six years ago today, I said 'I do,' to this handsome fella," Underwood, 33, captioned a photo of the pair dining on a clifftop in Cabo, Mexico, where they are holidaying to mark the milestone.

"I meant it then and I mean it now. God put us together and continues to bless our marriage. I couldn't imagine this life without you, @mfisher1212 I am thankful for these past six years together (and, of course, for our beautiful son, Isaiah) and I look forward to spending the rest of our lives in love."

Fisher, who shares 16-month-old Isaiah with Underwood, responded to his wife’s tribute with a photo from their wedding day, joking in the caption that his chart-topping wife – she is estimated to be worth $30m – was “marrying up.”

“Six years ago today we were married. Time sure does fly when you're having fun and you marry up. I'm very grateful to have an amazing wife and mother by my side!!” he wrote.